1. Field of the Invention
The present invention is in the field of fluid-flow couplings which are generally characterized as being of the “dry break” type. More particularly, the present invention relates to fluid-flow couplings which include a first (or male) part, and a second (or female) part which when connected to one another effect fluid-flow communication therebetween. When the coupling parts are connected they may be used to effect fluid-flow communication between a vessel and a conduit, for example. When the coupling parts are disconnected they mutually reseal so that fluid is not lost either from the conduit or from the vessel. Further, the present invention relates to such couplings which additionally have a guide structure removably supporting on one of the coupling parts, and guiding the other coupling part reciprocally for engagement and disengagement with the one coupling part. Further the present invention relates to such couplings that utilize a rotary handnut in order to complete the coupling and uncoupling act, thus providing for a reduced level of manual force to be applied to the coupling.
2. Related Technology
A conventional coupling structure is known in accord with U.S. Pat. No. 4,421,146 (the '146 patent), issued 20 Dec. 1983 to Curtis J. Bond, et al. A coupling structure according to the '146 patent includes a tubular spout attached to and in fluid communication with a fluid filled vessel, such as a bag held within a cardboard box. This spout portion includes a plug member which is axially moveable between a first position closing fluid communication between the vessel and an outer portion of the spout member, and a second position opening this fluid communication. In the second position of the plug member a pair of lateral openings at an inner portion of the plug member are moved inwardly of the spout to permit fluid communication between the vessel and the outer portion of the spout.
A service member (i.e., the male coupling part) of the Bond '146 patent is carried in a guide structure which clamps to the spout and guides the service member for axial sliding engagement into sealing relation with the spout. The service member provides communication with a conduit, and includes a valve member closing communication between the conduit and ambient when the service member is disconnected from the spout. The service member as it engages the spout is also engageable with the plug member to move it between its two positions, and engagement between the service member and plug member opens the valve in the service member. Thus, when the service member is engaged into the spout, communication between the vessel and the conduit is established. Further, it is seen that the plug member of the Bond '146 patent carries an axial projection which contacts the valve member of the service member (the male coupling part), and opens this valve member.
The service member of the Bond '146 patent cannot be conveniently opened for cleaning, inspection, or replacement of the sealing member therein. It is true that the service member can be disassembled manually, but this service member contains many parts, and after the service member has been used to convey a food product, its disassembly is a messy job. Consequently, these conventional service members are sometimes discarded when a simple cleaning or replacement of an O-ring seal would allow their continued use. Again, however, because the service member according to the Bond '146 patent cannot be conveniently cleaned or fitted with a new O-ring, many users simply throw the fitting away and purchase a new one.
Another conventional coupling, which may be considered to be of hermaphrodite configuration, is known from European patent application No. 0 294 095 A1, published 7 Dec. 1988 (the '095 application). According to the '095 application, a “male” and “female” coupling parts are brought into alignment and juxtaposition by a yoke carried on a guide housing. The male coupling part is configured as a tubular member which is axially movable by a handle on the guide housing to engage with an annular valve member carried in the female coupling part. When the male and female coupling parts are coupled with one another (i.e., by extension of the male coupling part relative to the guide housing and into the female coupling part), an inner liquid extraction flow path is separated from an outer air-entrance (or pressurized gas delivery) flow path by the annular valve member of the female coupling. In the coupled condition of the male and female couplings, the annular valve member of the female coupling part also serves as a sealing member. A version of this coupling is also known in which the male coupling part carries a spring-loaded internal disk valve member which closes the liquid extraction flow path of the male coupling part when the male and female coupling parts are not coupled with one another.
Further, in a conventional coupling known in accord with U.S. Pat. No. 5,816,298, issued 6 Oct. 1998, and assigned to the same assignee at the present application. In this coupling structure two hands were required to push the sleeve of the male part up into the female part in order to disengage the plug of the female fitting and allow fluid flow through the male sleeve. In the '298 patent the coupling utilizes a pair of opposite ears, which protrude from oppose sides of the guide portion of the male coupling member. The purpose of these ears is to allow a user of the coupling to manually push the sleeve of the male coupling part axially into the female coupling part in order open both coupling parts and allow fluid flow through the engaged coupling parts. This engagement of the coupling parts required a two step process as is described below.
The conventional coupling according to the '298 patent employs a two part axial forward movement and a two part axial rearward movement. The first movement part begins with the sleeve of the male coupling part in a fully retracted position and ends when the sleeve makes contact with the cap of the female coupling part. This movement is accomplished by the user pushing on the ears of the male coupling part so that the sleeve moves in a forward toward the female part. This movement should require a minimal amount of force. The second movement part requires more force because the user is required to push the ears of the male coupling part until the sleeve disengages the plug in the female part from it's sealed position, and engages this plug onto the distal end of the male coupling part, thus allowing fluid flow through the engaged coupling parts. At this time a spring of the male coupling part is compressed and a latch on the male coupling part engages onto a ledge or flange of the female coupling part. This engagement of the latch locks the two coupling parts together, thus providing a secure engagement of the two coupling parts during fluid flow.
Disengagement of the conventional coupling according to the '298 patent is accomplished by unlatching the latch, and squeezing with the fingers on a rear flange of the guide portion of the male coupling part and the pair of ears. This action sequentially disengages the latch from the ledge or flange of the female coupling part, and subsequently allows the combination of spring force and manually applied force to both withdraw the male coupling part from within the female coupling part, and to push the sleeve of the male coupling part back to a sealing position so as to shut off fluid flow from the male coupling part. Withdrawal of the male coupling part also positions and engages the plug of the female coupling part once again into a sealing position. Thus, fluid flow through the disengaged coupling parts is prevented. In order to disengage the male coupling part from the female coupling part, a considerable manually applied force is required. In order to apply this manual withdrawal force, once again two bands are required, and are used to apply a balanced squeeze between the ears of the male coupling part and a flange at the rear of this coupling part in order to effect a withdrawal force on the probe portion of the male coupling part. This withdrawal force withdraws the male probe from the female coupling part, and also restores the plug of the female coupling part to a sealed position within the female coupling part.